using System;
using System.Text;

using Org.BouncyCastle.Utilities;

namespace Org.BouncyCastle.Asn1
{
	public class DerGeneralString
		: DerStringBase
	{
		private readonly string str;

		public static DerGeneralString GetInstance(
			object obj)
		{
			if (obj == null || obj is DerGeneralString)
			{
				return (DerGeneralString) obj;
			}

			throw new ArgumentException("illegal object in GetInstance: "
					+ obj.GetType().Name);
		}

		public static DerGeneralString GetInstance(
			Asn1TaggedObject	obj,
			bool				isExplicit)
		{
			Asn1Object o = obj.GetObject();

			if (isExplicit || o is DerGeneralString)
			{
				return GetInstance(o);
			}

			return new DerGeneralString(((Asn1OctetString)o).GetOctets());
		}

		public DerGeneralString(
			byte[] str)
			: this(Strings.FromAsciiByteArray(str))
		{
		}

		public DerGeneralString(
			string str)
		{
			if (str == null)
				throw new ArgumentNullException("str");

			this.str = str;
		}

		public override string GetString()
		{
			return str;
		}

		public byte[] GetOctets()
		{
			return Strings.ToAsciiByteArray(str);
		}

		internal override void Encode(
			DerOutputStream derOut)
		{
			derOut.WriteEncoded(Asn1Tags.GeneralString, GetOctets());
		}

		protected override bool Asn1Equals(
			Asn1Object asn1Object)
		{
			DerGeneralString other = asn1Object as DerGeneralString;

			if (other == null)
				return false;

			return this.str.Equals(other.str);
		}
	}
}
